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b337528f MV |
1 | (define-module (ice-9 pretty-print)) |
2 | ||
3 | (export pretty-print) | |
4 | ||
5 | ;; From SLIB. | |
6 | ||
7 | ;;"genwrite.scm" generic write used by pretty-print and truncated-print. | |
8 | ;; Copyright (c) 1991, Marc Feeley | |
9 | ;; Author: Marc Feeley (feeley@iro.umontreal.ca) | |
10 | ;; Distribution restrictions: none | |
11 | ||
12 | (define genwrite:newline-str (make-string 1 #\newline)) | |
13 | ||
14 | (define (generic-write obj display? width output) | |
15 | ||
16 | (define (read-macro? l) | |
17 | (define (length1? l) (and (pair? l) (null? (cdr l)))) | |
18 | (let ((head (car l)) (tail (cdr l))) | |
19 | (case head | |
20 | ((quote quasiquote unquote unquote-splicing) (length1? tail)) | |
21 | (else #f)))) | |
22 | ||
23 | (define (read-macro-body l) | |
24 | (cadr l)) | |
25 | ||
26 | (define (read-macro-prefix l) | |
27 | (let ((head (car l)) (tail (cdr l))) | |
28 | (case head | |
29 | ((quote) "'") | |
30 | ((quasiquote) "`") | |
31 | ((unquote) ",") | |
32 | ((unquote-splicing) ",@")))) | |
33 | ||
34 | (define (out str col) | |
35 | (and col (output str) (+ col (string-length str)))) | |
36 | ||
37 | (define (wr obj col) | |
38 | ||
39 | (define (wr-expr expr col) | |
40 | (if (read-macro? expr) | |
41 | (wr (read-macro-body expr) (out (read-macro-prefix expr) col)) | |
42 | (wr-lst expr col))) | |
43 | ||
44 | (define (wr-lst l col) | |
45 | (if (pair? l) | |
46 | (let loop ((l (cdr l)) | |
47 | (col (and col (wr (car l) (out "(" col))))) | |
48 | (cond ((not col) col) | |
49 | ((pair? l) | |
50 | (loop (cdr l) (wr (car l) (out " " col)))) | |
51 | ((null? l) (out ")" col)) | |
52 | (else (out ")" (wr l (out " . " col)))))) | |
53 | (out "()" col))) | |
54 | ||
55 | (cond ((pair? obj) (wr-expr obj col)) | |
56 | ((null? obj) (wr-lst obj col)) | |
57 | ((vector? obj) (wr-lst (vector->list obj) (out "#" col))) | |
58 | ((boolean? obj) (out (if obj "#t" "#f") col)) | |
59 | ((number? obj) (out (number->string obj) col)) | |
60 | ((symbol? obj) (out (symbol->string obj) col)) | |
61 | ((procedure? obj) (out "#[procedure]" col)) | |
62 | ((string? obj) (if display? | |
63 | (out obj col) | |
64 | (let loop ((i 0) (j 0) (col (out "\"" col))) | |
65 | (if (and col (< j (string-length obj))) | |
66 | (let ((c (string-ref obj j))) | |
67 | (if (or (char=? c #\\) | |
68 | (char=? c #\")) | |
69 | (loop j | |
70 | (+ j 1) | |
71 | (out "\\" | |
72 | (out (substring obj i j) | |
73 | col))) | |
74 | (loop i (+ j 1) col))) | |
75 | (out "\"" | |
76 | (out (substring obj i j) col)))))) | |
77 | ((char? obj) (if display? | |
78 | (out (make-string 1 obj) col) | |
79 | (out (case obj | |
80 | ((#\space) "space") | |
81 | ((#\newline) "newline") | |
82 | (else (make-string 1 obj))) | |
83 | (out "#\\" col)))) | |
84 | ((input-port? obj) (out "#[input-port]" col)) | |
85 | ((output-port? obj) (out "#[output-port]" col)) | |
86 | ((eof-object? obj) (out "#[eof-object]" col)) | |
87 | (else (out "#[unknown]" col)))) | |
88 | ||
89 | (define (pp obj col) | |
90 | ||
91 | (define (spaces n col) | |
92 | (if (> n 0) | |
93 | (if (> n 7) | |
94 | (spaces (- n 8) (out " " col)) | |
95 | (out (substring " " 0 n) col)) | |
96 | col)) | |
97 | ||
98 | (define (indent to col) | |
99 | (and col | |
100 | (if (< to col) | |
101 | (and (out genwrite:newline-str col) (spaces to 0)) | |
102 | (spaces (- to col) col)))) | |
103 | ||
104 | (define (pr obj col extra pp-pair) | |
105 | (if (or (pair? obj) (vector? obj)) ; may have to split on multiple lines | |
106 | (let ((result '()) | |
107 | (left (min (+ (- (- width col) extra) 1) max-expr-width))) | |
108 | (generic-write obj display? #f | |
109 | (lambda (str) | |
110 | (set! result (cons str result)) | |
111 | (set! left (- left (string-length str))) | |
112 | (> left 0))) | |
113 | (if (> left 0) ; all can be printed on one line | |
114 | (out (reverse-string-append result) col) | |
115 | (if (pair? obj) | |
116 | (pp-pair obj col extra) | |
117 | (pp-list (vector->list obj) (out "#" col) extra pp-expr)))) | |
118 | (wr obj col))) | |
119 | ||
120 | (define (pp-expr expr col extra) | |
121 | (if (read-macro? expr) | |
122 | (pr (read-macro-body expr) | |
123 | (out (read-macro-prefix expr) col) | |
124 | extra | |
125 | pp-expr) | |
126 | (let ((head (car expr))) | |
127 | (if (symbol? head) | |
128 | (let ((proc (style head))) | |
129 | (if proc | |
130 | (proc expr col extra) | |
131 | (if (> (string-length (symbol->string head)) | |
132 | max-call-head-width) | |
133 | (pp-general expr col extra #f #f #f pp-expr) | |
134 | (pp-call expr col extra pp-expr)))) | |
135 | (pp-list expr col extra pp-expr))))) | |
136 | ||
137 | ; (head item1 | |
138 | ; item2 | |
139 | ; item3) | |
140 | (define (pp-call expr col extra pp-item) | |
141 | (let ((col* (wr (car expr) (out "(" col)))) | |
142 | (and col | |
143 | (pp-down (cdr expr) col* (+ col* 1) extra pp-item)))) | |
144 | ||
145 | ; (item1 | |
146 | ; item2 | |
147 | ; item3) | |
148 | (define (pp-list l col extra pp-item) | |
149 | (let ((col (out "(" col))) | |
150 | (pp-down l col col extra pp-item))) | |
151 | ||
152 | (define (pp-down l col1 col2 extra pp-item) | |
153 | (let loop ((l l) (col col1)) | |
154 | (and col | |
155 | (cond ((pair? l) | |
156 | (let ((rest (cdr l))) | |
157 | (let ((extra (if (null? rest) (+ extra 1) 0))) | |
158 | (loop rest | |
159 | (pr (car l) (indent col2 col) extra pp-item))))) | |
160 | ((null? l) | |
161 | (out ")" col)) | |
162 | (else | |
163 | (out ")" | |
164 | (pr l | |
165 | (indent col2 (out "." (indent col2 col))) | |
166 | (+ extra 1) | |
167 | pp-item))))))) | |
168 | ||
169 | (define (pp-general expr col extra named? pp-1 pp-2 pp-3) | |
170 | ||
171 | (define (tail1 rest col1 col2 col3) | |
172 | (if (and pp-1 (pair? rest)) | |
173 | (let* ((val1 (car rest)) | |
174 | (rest (cdr rest)) | |
175 | (extra (if (null? rest) (+ extra 1) 0))) | |
176 | (tail2 rest col1 (pr val1 (indent col3 col2) extra pp-1) col3)) | |
177 | (tail2 rest col1 col2 col3))) | |
178 | ||
179 | (define (tail2 rest col1 col2 col3) | |
180 | (if (and pp-2 (pair? rest)) | |
181 | (let* ((val1 (car rest)) | |
182 | (rest (cdr rest)) | |
183 | (extra (if (null? rest) (+ extra 1) 0))) | |
184 | (tail3 rest col1 (pr val1 (indent col3 col2) extra pp-2))) | |
185 | (tail3 rest col1 col2))) | |
186 | ||
187 | (define (tail3 rest col1 col2) | |
188 | (pp-down rest col2 col1 extra pp-3)) | |
189 | ||
190 | (let* ((head (car expr)) | |
191 | (rest (cdr expr)) | |
192 | (col* (wr head (out "(" col)))) | |
193 | (if (and named? (pair? rest)) | |
194 | (let* ((name (car rest)) | |
195 | (rest (cdr rest)) | |
196 | (col** (wr name (out " " col*)))) | |
197 | (tail1 rest (+ col indent-general) col** (+ col** 1))) | |
198 | (tail1 rest (+ col indent-general) col* (+ col* 1))))) | |
199 | ||
200 | (define (pp-expr-list l col extra) | |
201 | (pp-list l col extra pp-expr)) | |
202 | ||
203 | (define (pp-LAMBDA expr col extra) | |
204 | (pp-general expr col extra #f pp-expr-list #f pp-expr)) | |
205 | ||
206 | (define (pp-IF expr col extra) | |
207 | (pp-general expr col extra #f pp-expr #f pp-expr)) | |
208 | ||
209 | (define (pp-COND expr col extra) | |
210 | (pp-call expr col extra pp-expr-list)) | |
211 | ||
212 | (define (pp-CASE expr col extra) | |
213 | (pp-general expr col extra #f pp-expr #f pp-expr-list)) | |
214 | ||
215 | (define (pp-AND expr col extra) | |
216 | (pp-call expr col extra pp-expr)) | |
217 | ||
218 | (define (pp-LET expr col extra) | |
219 | (let* ((rest (cdr expr)) | |
220 | (named? (and (pair? rest) (symbol? (car rest))))) | |
221 | (pp-general expr col extra named? pp-expr-list #f pp-expr))) | |
222 | ||
223 | (define (pp-BEGIN expr col extra) | |
224 | (pp-general expr col extra #f #f #f pp-expr)) | |
225 | ||
226 | (define (pp-DO expr col extra) | |
227 | (pp-general expr col extra #f pp-expr-list pp-expr-list pp-expr)) | |
228 | ||
229 | ; define formatting style (change these to suit your style) | |
230 | ||
231 | (define indent-general 2) | |
232 | ||
233 | (define max-call-head-width 5) | |
234 | ||
235 | (define max-expr-width 50) | |
236 | ||
237 | (define (style head) | |
238 | (case head | |
239 | ((lambda let* letrec define) pp-LAMBDA) | |
240 | ((if set!) pp-IF) | |
241 | ((cond) pp-COND) | |
242 | ((case) pp-CASE) | |
243 | ((and or) pp-AND) | |
244 | ((let) pp-LET) | |
245 | ((begin) pp-BEGIN) | |
246 | ((do) pp-DO) | |
247 | (else #f))) | |
248 | ||
249 | (pr obj col 0 pp-expr)) | |
250 | ||
251 | (if width | |
252 | (out genwrite:newline-str (pp obj 0)) | |
253 | (wr obj 0))) | |
254 | ||
255 | ; (reverse-string-append l) = (apply string-append (reverse l)) | |
256 | ||
257 | (define (reverse-string-append l) | |
258 | ||
259 | (define (rev-string-append l i) | |
260 | (if (pair? l) | |
261 | (let* ((str (car l)) | |
262 | (len (string-length str)) | |
263 | (result (rev-string-append (cdr l) (+ i len)))) | |
264 | (let loop ((j 0) (k (- (- (string-length result) i) len))) | |
265 | (if (< j len) | |
266 | (begin | |
267 | (string-set! result k (string-ref str j)) | |
268 | (loop (+ j 1) (+ k 1))) | |
269 | result))) | |
270 | (make-string i))) | |
271 | ||
272 | (rev-string-append l 0)) | |
273 | ||
274 | ;"pp.scm" Pretty-Print | |
275 | (define (pretty-print obj . opt) | |
276 | (let ((port (if (pair? opt) (car opt) (current-output-port)))) | |
277 | (generic-write obj #f 79 | |
278 | (lambda (s) (display s port) #t)))) | |
279 |